An anti-Islamic State Islamist group in the Libyan capital released a propaganda video detailing the confessions of five captured militants who say they took part in a half-dozen attacks in Tripoli. Their testimonies suggest IS is relying on inexperienced fighters for the bulk of its operations in the North African country, and that it is facing manpower challenges.

Even so, European governments remain highly alarmed at the quick rise of the terror group in Libya, and say that in the last six months IS may have nearly doubled the number of fighters there to 5,000.

The nearly hour-long video was released by the so-called Special Deterrence Force, a controversial 700-member Islamist militia under the command of 35-year-old Abd al-Rauf Kara, a Tripoli native.

Its narrator condemns the terror group, saying, "Islam has never been a terrorist religion."

But security analysts say the testimonies of the five militants, all but one under the age of 30, suggest Islamic State militants are in the early stages of their buildup — at least when it comes to Tripoli — and may have trouble infiltrating fighters into the Libyan capital.

"If the information presented in this video is accurate, it is a testament to the weakness of IS operating in Tripoli, showing that they relied on a small group of inexperienced and untrained members for the bulk of their operations within the capital," said a security analyst who asked not to be identified.

FILE - Civilians and security personnel survey the scene of an explosion at a police station in Tripoli, Libya, a blast later claimed by militants professing loyalty to the Islamic State, March 12, 2015.

"Simultaneously, it underlines the ability of a disposable group to conduct targeting within a major city that lacks any unified security forces," he added.

Gaining media attention

The five captured militants say they were involved in a number of attacks, including the bombings last year of the Egyptian and Emirati embassies and two security buildings in the Libyan capital, and attacks this year on the Algerian embassy and the U.N. mission. One of the militants says the aim of the Algerian embassy bombing was to attract publicity.

The importance of gaining media attention is mentioned several times in connection with the other attacks, too.

All the attacks received media coverage, adding to the sense of Western foreboding about the Islamic State's rapid presence in Libya.

Earlier this month, a group of U.N. experts said in a report that the Islamic State has had trouble expanding in Libya due to a shortage of fighters.

While noting that Libya — which has been divided for more than a year between two rival governments, as well as by other factions — represents the most vulnerable of countries in the region, the U.N. experts said the group faces several constraints in Libya, including the fact that, "It is only one player among multiple warring factions in Libya."

Rushed training, planning

The U.N. analysts said the terror group is having problems forming and maintaining alliances with local militias. According to the report, the IS affiliate relies on about 800 Libyan veterans who have returned from Syria and Iraq, but that most of the rest are locally recruited, and they appear to have little training. One of the militants in the video noted he had just days at a training camp.

Planning for the operations seems as rushed as the training — the attack on the Tripoli security directorate took just two days, the militants say, and the bomb consisting of rockets packed into a car failed to detonate properly when triggered by a cellphone call.

FILE - In this image made from video, the Corinthia Hotel is seen under attack in Tripoli, Libya, Jan. 27, 2015.

Kara's Special Deterrence Force has clashed several times with IS, most notably last January when his men were the first on the scene to battle jihadists who had stormed the landmark and killed 10 people as they went looking for Westerners to slaughter. An American security contractor staying at the hotel was killed in the attack.

The captured militants on the video released by the SDF only provided "material assistance" for the Corinthia Hotel attack — a far more sophisticated operation that was carried out by more experienced fighters.

Threat of growth

But in an exclusive interview with this correspondent several months ago, Kara, who rarely speaks with Western journalists, warned that IS in Libya is likely to grow exponentially unless order is restored to Libya quickly. He estimated that IS has about 2,000 fighters in Libya — although some of his lieutenants put the number closer to 3,000. Some Western officials think IS may have as many as 5,000 fighters now.

In recent weeks, the terror group has been using social media accounts to call for more jihadists to go to Libya. Abdulrahman Moftah Almzogee, the youngest of the militants on the SDF video, says that the recent recruits he saw in Sirte were "mostly Libyans and Tunisians," but there were others from European countries, including Britain, Spain and Russia.